Pivotal Engineering of Christchurch, New Zealand has designed and built a new two stroke engine. The pivotal engine utilizes a pivoting wedge shaped piston that pivots on a shaft while the driving force is transferred by a connecting rod from the bottom of the piston to the crankshaft. The piston itself is directly cooled by water which circulates through the piston from the pivot shaft. The water cooled piston allows precise temperature control not previously possible.
The pivot motion eliminates the rocking motion of the piston in a conventional piston two stroke, dramatically reducing wear during cold startups, it controls the seals so they work more efficiently and dramatically reduces oil consumption to 10 percent of a conventional two stroke.
Although many applications are suitable for this engine, it was actually conceived to overcome durability problems in two stroke GP motorcycles and therefore is very well suited to everything from commuter scooters to high performance bikes.
There is an extensive discussion on the site of the pivotal engine’s suitability for use as a hydrogen powered internal combustion engine along with the necessary requirements for any engine designed to burn hydrogen directly and why the pivotal engine addresses these issues so well. The engine can also be designed to run on compressed natural gas.
The Flash animation on their site, which you really need to see, makes the operation of the engine very clear and it looks quite promising. Now this is a hydrogen motorcycle engine I could like!
aaron says
I think I bookmarked this a while ago, and haven’t got around to looking at it. that or there’s another funny shape piston thing out there. water cooled piston though? didn’t catch that in the quick scan I did…..cool.
hoyt says
New Zealand at it again ! thanks
Joe vonDohlen says
The technology of this engine is amazing. What are your plans to do with your engine? Does the kneeslider offer a motorcycle with a pivitol piston engine? Anything available in the U.S.? I live in Santa Rosa, California, United States.
Sean says
Wow, stumbled across this while reading up about the Smartuki. I live in Christchurch, New Zealand… It’s awesome to hear that my hometown is actually putting out some decent technology!
GAry Lee says
This engine was shown at AirVenture in 2003. Since then it is difficult to find new material on it. I have been waiting anxiously to get my hands on an engine, but they do not seem to be available, even as a prototype. I have a couple of older bikes I am just waiting to upgrade with this engine. If anyone knows how to get their hands on one I would be interested.
jamie says
i am a student studying at exeter college, exeter uk EX2 8QF
i am interested in this motorcycle design and could you send me more information on it.
derek brandenburg says
I am a student at motorcycle mechanics institute in phoenix AZ, and am doing a presentation on unique piston designs. I am very intrigued about this subject and would like to recieve as much info as possible about it. please e-mail me info about the pros and cons of a pivotal piston design.
thank you
Derek B
Emilya Davis says
Can we run our car with water and gas?
Can anybody tell me is the HHO Gas is real working or is another scam?
jack says
it seems like another (wankel) rotary seal problem has this been tested and what kind of seal material is used? nice original thinking!
satish says
what about mailage?
is how better than existing engines